1. Field of the Invention
This invention relates generally to damper devices for dampening the opening and closing of an openable object such as a door, ashtray, chest or the like relative to a main body. More particularly, the present invention relates to an improved air damper of a unique construction which includes dual controllable orifice means for enabling the openable object of a varying load, such as a glove compartment door, to be opened gently from a closed state.
2. Description of the Prior Art
As is generally known in the art, if an openable object is allowed to abruptly open relative to its main body the impact between them may not only cause damage to occur possibly destroying both of them, but can also produce vibration and noise to render the contents stored within the openable object to fall out and become scattered. For example, when the openable object is a glove compartment door installed in the interior of an automotive vehicle the sudden impact opening Will cause the items therein to be tossed or thrown all over the passenger, seat and floor of the car. In order to avoid this type of problem, there has been provided in the prior art damper devices for absorbing the impact created between the main body and the openable object.
A state-of-the-art search directed to the subject matter of this application in the U.S. Patent and Trademark Office uncovered the following U.S. Letters Patent:
______________________________________ 2,063,526 4,629,167 2,881,467 4,856,625 3,593,367 4,974,285 ______________________________________
There is disclosed in U.S. Pat. No. 2,063,526 to W. F. Snowdon issued on Dec. 8, 1936, a door check formed of a tubular casing 1 with springs 15 and 16, friction retarding elements 21 and 22, and a wedge 20. One end of the casing is typically held to the door frame 9 and a rod 18 extending from the other end is typically attached to the door 23. The interior is arranged so that as the door opens the springs are readily compressed for easy opening. As the door is released the springs automatically close the door and at the same time force the wedge 20 into the friction elements 21 and 22 which bear against the inner surface of the casing retarding the closing of the door until the friction elements reach an enlarged part of the casing. At that time, the friction elements are released so as to permit a gradual and final closing movement of the door.
There is disclosed in U.S. Pat. No. 2,881,467 to J. Struhar issued on Apr. 14, 1959, a door check and closer which is comprised of essentially two pistons 31, 45 and two cylinders 20, 30 telescopically arranged with two compressed springs 28, 40 resisting their telescopic extension. When the pistons 31, 45 are moved to the left relative to FIG. 3 of the '467 patent, during initial door opening, air will be forced through the vents 29 and 50 to make for easy initial door opening until these pistons pass over the vents and begin compressing air in chamber B of the cylinder 20 and chamber C of the cylinder 30. Conversely, when the pistons 31, 45 are rapidly moved to the right relative to FIG. 4 of the '467 patent by recoil of both springs 28 and 40 past the vents 29 and 50, air is trapped and compressed in the air chamber A of the cylinder 20 and in the air chamber D of the cylinder 30 to cushion door closing.
In U.S. Pat. No. 3,593,367 to R. W. Waldo issued on Jul. 20, 1971, there is taught a pneumatic door closer which includes an elongated casing 8 and piston means. The piston means includes a body structure defining a radially outwardly opening annular channel 28 having axially spaced side walls. The piston means further includes a sealing ring 38 movable axially toward and away from one of the side walls and a porous lubricating ring 39 disposed between the other one of the side walls and the sealing ring. Both rings frictionally engage the cylindrical surface of the casing 8 in which the piston means is axially movable. The piston means includes a pair of cooperating elements welded together and to the inner end of the plunger rod 12 which extends axially outward of one end of the casing.
In U.S. Pat. No. 4,629,167 to S. Kimura et al. issued on Dec. 16, 1986, there is taught a piston-cylinder type damper which includes a cylinder 11 connected to either member of the pair of a main body and an openable object, and a piston 12 connected to the other member of the pair and adapted to fit into the cylinder 11. The piston 12 incorporates therein a check valve 16 adapted to allow the air in the cylinder to escape from the cylinder interior while the piston is driven into the cylinder by the movement of the openable object. On the other hand, when the piston is being withdrawn from the cylinder the check valve is kept closed thereby creating the dampening action.
In U.S. Pat. No. 4,856,625 to T. Oshida issued on Aug. 15, 1989, there is described a cylinder type damper device for dampening the opening and closing movement of a storage box. The damper device includes a cylinder member 4 enclosing air therein, an end cap 10 with a filter 18 therein, and a rod 6 reciprocally movably inserted into the cylinder member. The front end of the rod is provided with a piston 5 for dividing the interior of the cylinder member 4 into a head chamber 4a and a rod chamber 4b. The piston 5 has an orifice 7 formed throughout its entire length in the axial direction thereof and being for interchanging air in the head and rod chambers by the axial movement thereof. The piston 5 also has air holes 9 which are likewise formed throughout its entire length in the axial direction thereof. A check valve 8 is provided for blocking the interchanging of air between the head and rod chambers in accordance with the one directional movement in the axial direction of the piston.
Finally, there is disclosed in U.S. Pat. No. 4,974,285 to L. Enrietti issued on Dec. 4, 1990, a device for assisting in the opening and closing of a pivotally mounted member. The device includes an elongated housing a cylindrical slide 2 mounted slidably in the housing, a helical spring 3 mounted between the housing and the slide for retaining the slide in the housing in a retracted position, and braking devices for retarding movement of the slide in either direction. The braking devices comprise two small nozzle-shaped orifices 5 formed in the end wall 4 of the housing 1 through which air has to flow into and out of as the slide moves relative to the housing.
However, none of the prior art uncovered in the search disclosed an air damper of a unique construction like that of the present invention which includes dual controllable orifice means for enabling the openable object of a varying load, such as a glove compartment door, to be opened gently from a closed state.